Zero Forcing on 2-connected Outerplanar Graphs

We determine upper and lower bounds on the zero forcing number of 2-connected outerplanar graphs in terms of the structure of the weak dual. We show that the upper bound is always at most half the number of vertices of the graph. This work generalizes work of Hern\'andez, Ranilla and Ranilla-Cortina who proved a similar result for maximal outerplanar graphs

Association of masking policies with mask adherence and distancing during the SARS-COV-2 pandemic

BACKGROUND: Quantification of the impact of local masking policies may help guide future policy interventions to reduce SARS-COV-2 disease transmission. This study\u27s objective was to identify factors associated with adherence to masking and social distancing guidelines. METHODS: Faculty from 16 U.S. colleges and universities trained 231 students in systematic direct observation. They assessed correct mask use and distancing in public settings in 126 US cities from September 2020 through August 2021. RESULTS: Of 109,999 individuals observed in 126 US cities, 48% wore masks correctly with highest adherence among females, teens and seniors and lowest among non-Hispanic whites, those in vigorous physical activity, and in larger groups (P \u3c .0001). Having a local mask mandate increased the odds of wearing a mask by nearly 3-fold (OR = 2.99, P = .0003) compared to no recommendation. People observed in non-commercial areas were least likely to wear masks. Correct mask use was greatest in December 2020 and remained high until June 2021 (P \u3c .0001). Masking policy requirements were not associated with distancing. DISCUSSION: The strong association between mask mandates and correct mask use suggests that public policy has a powerful influence on individual behavior. CONCLUSIONS: Mask mandates should be considered in future pandemics to increase adherence

C4 article: implications of COVID-19 in transplantation

A novel coronavirus has had global impact on individual health and health care delivery. In this C4 article, contributors discuss various aspects of transplantation including donor and recipient screening, management of infected patients, and prevention of coronavirus disease (COVID). Donor screening with SARS-CoV-2 nucleic acid testing (NAT) close to the time of procurement is recommended. Many programs are also screening all potential recipients at the time of admission. The management of COVID has evolved with remdesivir emerging as a new potential option for transplant recipients. Dexamethasone has also shown promise and convalescent plasma is under study. Prevention strategies for transplant candidates and recipients are paramount. Pediatric-specific issues are also discussed. Strategies for the psychological well-being of patients and providers are also imperative, in addition to future research priorities for transplantation